I have developed an Android application which allows remotely control (CAT) your transceiver through Bluetooth. It supports for the moment a limited number of transceivers: Yaesu FT817, 857 and 897.
If enough interest, other brands / models will be supported in the future.
The application is still in an early development phase, has bugs, does not support any kind of Android device or resolution, but I decided to publish it now and with your help to speed up the process of development and improvement.

Some of the available features (as in version 0.1):
- Can control through Bluetooth Yaesu FT-817/857/897 transceivers (tested only on FT817);
- supports the following display resolutions: 1280x800 (ex. Galaxy TAB 10,8.9,7.7), 1280x720 (ex. Galaxy S3),1024x600(ex. Galaxy TAB 7),800x480 (ex. Galaxy S, S2),480x320(ex, Sony Xperia mini),320x240 (some low end models)
- Large digits to display frequency
- Directly switch to any HAM band or select a custom frequency range (anywhere where permitted by the transceiver);
- Select through a wheel one of the following frequency steps: 0.01, 0.1, 1, 2.5, 5, 6.25, 12.5 or 25KHz. Current step is displayed;
- Display currently selected power level;
- Display the mode that can be used for the current frequency, according with IARU regulation, or “noHAM” for frequencies outside the HAM bands;
- CB band available through the 10m band button;
- Select through a wheel one of the following operation modes: LSB, USB, W, CWR, AM, FM, DIG, PKT;
- ON/OFF transmitter (only if it was previously powered on through the hardware button – this is a transceiver limitation);
- Display during RX the S control (from S0 to S9+60dB), including in graphical mode (16 steps);
- Display during TX , in the same time: SWR, PWR, ALC, MOD, both in graphic and numerical value;
- Tune (with preselected steps) through a rotary knob or +/- buttons;
- Directly enter the frequency from a large numeric keypad;
- Lock the screen to prevent accidental changes ;
- You can PTT the transceiver both from the smartphone/tablet screen or from the Mic PTT button. The application automatically detect PTT status, independent of PTT source;
- For demo purpose (or further for memories configuration), application can be used in both online (Bluetooth) or Offline (not connected) modes.

Some of the known limitations are:
- Memories function not yet implemented;
- SQUELCH, SCAN and SHIFT not yet implemented;
- The device is supported only in landscape mode (except Startup page);
- Except S control, all other measured parameters are not yet calibrated;
- A limited number of tests were performed on a Galaxy TAB 7.7(P6800) with Android 4.0.4 and Sony Xperia Mini ST15i. The other resolutions were tested on emulator. Application for sure still has bugs, or can crash for no apparent reason. With your help issues will be solved one by one and new features will be added.

You can find more details about the application and a link for download on my web page (see signature).
A forum is available to discuss all the problems related to the application.http://www.yo3ggx.ro/forum/bt8x7

Please send me your feedback if you have a chance to play with the application. This is possible even in Offline mode (without a Bluetooth interface).
If you have an Android device with another resolution, please send me the model and the info you get from the application splash screen (width, height and scale).